SFC /SCANNOW Command - System File Checker

How to Repair Windows 7 System Files with System File Checker​

   Information

The sfc /scannow command (System File Checker) scans the integrity of all protected Windows 7 system files and replaces incorrect corrupted, changed/modified, or damaged versions with the correct versions if possible.

   Tip

If you get the Windows Resource Protection Could Not Start the Repair Service error when trying to run SFC, then make sure that the Windows Modules Installer service is enabled, click on Start, and set to Manual.

Services - Start or Disable

OR

Copy and paste the command below in the elevated command prompt, and press Enter. After the Windows Modules Installer service has started, try running the SFC command again

net start trustedinstaller

   Note

The KB3022345, KB3035583, and KB3068708 updates will cause SFC to give you a false mismatch message in SFC for files related to these updates.

You can safely ignore these results in your SFC details since it will not affect SFC from being able to repair other system files.

   Warning

Be aware that if you have modified your system files as in theming explorer/system files, running sfc /scannow will revert the system files such as explorer.exe back to it's default state. Make the appropriate backups of your system files that you have modified for theming if you wish to save them before running sfc /scannow.

:note: For the updated Windows 10 tutorial, please see - SFC Command - Run in Windows 10 - Windows 10 Tutorials

CONTENTS:

• Option One: To Run the SFC /SCANNOW Command at Boot
• Option Two: To Run the SFC /SCANNOW Command in Windows 7
• Option Three: How to See and Read Only the "SFC" Scan Results from the CBS.LOG

OPTION ONE

To Run the SFC /SCANNOW Command at Boot

1. For how, see METHOD TWO at this link: SFC /SCANNOW : Run in Command Prompt at Boot

   Note

Using OPTION TWO below is recommended if able.

If you would like to get help with your SFC issue, then be sure to upload and attach your sfcdetails.txt file from OPTION THREE below in your post.

OPTION TWO

To Run the SFC /SCANNOW Command in Windows 7

1. Open an elevated command prompt or an elevated PowerShell, and do step 2 or 3 below for what type of scan you would like to run.


2. To Scan and Repair System Files
NOTE: Scans the integrity of all protected system files and repairs the system files if needed. Please see red WARNING box at the top of this tutorial.
A) In the elevated command prompt, type sfc /scannow, press Enter, and go to step 4 below. (see screenshot below)
NOTE: This may take a little bit to finish.


3. To Only Verify if the System Files are Corrupted
NOTE: Scans and only verifies the integrity of all proteced system files only. This command will not change your system files as in the red WARNING box at the top of this tutorial.
A) In the elevated command prompt, type sfc /verifyonly, press Enter, and go to step 4 below.
4. When the scan is complete, hopefully you will see all is ok like the screenshot below.

   Note

• If SFC could not fix something, then run the command again to see if it may be able to the next time. Sometimes it may take running the sfc /scannow command 3 or more times to completely fix everything that it's able to.
• If not, then download and run the 32-bit (x86) or 64-bit (x64) System Update Readiness Tool for your same installed 32-bit or 64-bit Windows 7, restart the PC afterwards, and try the sfc /scannow command again.
• If still not, then try using OPTION ONE above to run the sfc /scannow command at boot.
• If still not, then you can attempt to run a System Restore using a restore point dated before the bad file occured to fix it. You may need to repeat doing a System Restore until you find a older restore point that may work.
• If still not, then you can use the steps in the TIP box in the OPTION THREE section below to manually replace the files that SFC could not fix if there are not to many fix.
• If there are to many files to manually fix, or you prefer not to use OPTION THREE below, then you could do a repair install without losing anything.

If you would like to get help with your SFC issue, then be sure to upload and attach your sfcdetails.txt file from OPTION THREE below in your post.

5. When done, close the elevated command prompt.

OPTION THREE

How to See and Read Only the "SFC" Scan Results from the CBS.LOG

   Note

When SFC runs, it logs it's actions into the C:\Windows\Logs\CBS\CBS.log. The steps in this option will show you how to see only the specific SFC entries with the [SR] tags in this CBS.log. This can be helpful to show you what files SFC could not fix automatically if you wanted to try and manually replace them.

1. Open an "elevated command prompt" (right click -> Run as administrator).

2. In the elevated command prompt, copy and paste the command below, and press Enter. (See screenshot below)
NOTE: This will place a sfcdetails.txt file on your desktop with only the SFC scan result details from the CBS.LOG in it.

findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log >"%userprofile%\Desktop\sfcdetails.txt"

3. Close the elevated command prompt.

4. Open the sfcdetails.txt file on your desktop to see the SFC scan details in the CBS.LOG.

5. You can safely delete the sfcdetails.txt file afterwards if you like.

   Tip

If you need to replace a corrupted system file that SFC cannot fix, then this will show you how to by extracting a new copy directly from your Windows 7 installation DVD.

Extract Files from Windows 7 Installation DVD

That's it,
Shawn

Related Tutorials

---

• How to Run the System File Checker in a Command Prompt at Boot
• How to Do a System Restore in Windows 7
• How to Do a Repair Install to Fix Windows 7
• How to Run Disk Check in Windows 7
• How to See Windows 7 Reliability and Problem History with Reliability Monitor
• How to Extract Files from the Windows 7 Installation DVD
• How to Troubleshoot a Problem by Performing a Clean Startup in Windows 7 or Vista

 

[techneis]

After SFC scan "Windows Resource Protection found corrupt files" error

Hi,
Thanks for the brilliant posts!!
Tried to install a transformation pack but meanwhile got an error "BOOTMGR corrupt, unable to boot"...later googled & followed your posts & tried the steps as mentioned in ur posts. But now after the sfc scan it shows an error as "Windows Resource Protection found corrupt files but was unable to fix some of them. details are included in CBS.log. windir\logs\CBS\CBS.log For example C:\Windows\logs\CBS\CBS.log".
kindly suggest how to proceed & recover the OS...!!

 

[Brink]

Hell Techneis, and welcome to Seven Forums.

If you like, go ahead and do OPTION THREE to post back with your uploaded sfcdetails.txt file. I'll be happy to take a look at it.

 

[sei]

Hi,

Sorry to disturb you, but after running a sfc /scannow command, I have some dammages files which are the msi.dll (I put my report in joined files)

I read all the topics and the tutorials and know what to do now thanks to you.

But when I bought my pc, I didn't have the Windows 7 home premium installation cd because it's a Sony Vaio (and they don't give the OS intallation cd anymore but make you to burn a reinstallation cd...) and I don't want to reinstall the whole thing. I just need a clean msi.dll, Can someone upload it for me please ?

Thank you in advance.

 

[Slartybart]

sei: This should help you get your system files back in order. It's a large download and runs for quite a while.
System Update Readiness Tool for Windows 7 for x64-based Systems (KB947821) [September 2012]

 

[sei]

Slartybat : Thank you sooooooo much ! It's working I can install new programs again ! You were so fast ! Thank you again !

 

[Slartybart]

sei: glad to be of assitance. I onced worked at SEI (Valley Forge, PA)

 

[superboy123]

Hello,i have one problem,,why after 12 percent scan its show warning its says 'windows resources protection could not perform the rrquest operation.

 

[shinyjanjan]

Does the corrupted files affects system performance? What is the benefit of repairing system files? Thank you for this very informative tutorial!!

 

[Brink]

Hello Jan,

It really depends on what system files have been modified, corrupted, or missing. Some could affect system performance, while others may only affect you being able to do something. If the file had been modified by you, then it will be considered to be corrupted since it's not default.

The main benefit of running a "sfc /scannow" command is to restore any modified, corrupted, or missing system files back to their default state.

 

[djbillyd]

sfc /scannow

Ran the scan, but when I went to C:WINDOWS\logs\cbs, I couldn't open the CBS text file. I got a message "Access Denied". Say what?

 

[Golden]

Ran the scan, but when I went to C:WINDOWS\logs\cbs, I couldn't open the CBS text file. I got a message "Access Denied". Say what?

That message is normal - copy the file to a different location, and then open it.

 

[Brink]

Ran the scan, but when I went to C:WINDOWS\logs\cbs, I couldn't open the CBS text file. I got a message "Access Denied". Say what?

Hello Billy, and welcome to Seven Forums.

Please see OPTION THREE in the tutorial below to create a sfcdetails.txt file instead.

Hope this helps,
Shawn

 

[djbillyd]

Thanks man! It seems to be working well, right now. Everything loads as quickly as it should.

Good job!

 

[Brink]

You're welcome Billy. I'm glad that we could help.

 

[djbillyd]

Well, it's doing the same thing again. I ran the process and couldn't get the details.txt document to post.

 

[Brink]

Billy,

Maybe a mistake made in the command, but you should be able to also copy the CBS.log file to your desktop, then be able to open the CBS.log from the desktop.

 

[djbillyd]

Yeah, that's what I've been doing. And when I say "doing", I mean doing! My Windows explorer just stops working. I don't understand why it just keeps doing it. When I run the file checker, the log says: "2012-11-23 20:35:51, Info CSI 00000309 [SR] Verify and Repair Transaction completed. All files and registry keys listed in this transaction have been successfully repaired". But if I don't reboot, my explorer is still stuck on stupid. When I DO reboot, it works fine. Then, for whatever reason, it goes dumb again and won't open.

Does anyone know why explorer does that, other than the file checker thing? It's irritating. I am not even sure if reinstallin "7" would do any good. I've done that once already...

 

[djbillyd]

Step 2-In the elevated command prompt, copy and paste the command below and press Enter. (See screenshot below)

How can you paste in the cmd box? I haven't been able to get that to work. I remember doing it a while back when doing an install of an ADTRAN router. But this "paste" does not seem to take...

 

[djbillyd]

CAncel the copy and paste post. I found out how to do that.

But the rest of the repair process is bumming me out, big time. I am running into a "Try Again" dialogue box that just keeps popping up. I have done everything with Administrator Permission. But this box won't let the process continue. What now?

 

[Brink]

Billy, with all the trouble you are having with this, you might consider a repair install.